The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Biometric identification represent an objective measurement of one or more distinguishing biological traits (biometric characteristic) of an individual which can be stored in a database to enable comparison with other entries in the database for unique identification and verification of an individual. The most traditional form of biometric verification is fingerprinting. However, other biometric traits such as facial or other bodily characteristics (hand geometry, earlobe geometry, finger-vein, palm-vein, retina and iris patterns) have been used for biometric identification/verification purposes. Still further biometric traits that have been used are the spectral characteristics of a human voice, odor, and dental records. Even DNA and other physiological features/characteristics have been used to date in connection with biometric verification systems.
The digitizing of the information using computers has revolutionized the use of biometric technologies. Such digitizing of information has enabled automated operation of biometric verification systems, and is expected to become a major factor in the future, in part because of the ability to be easily integrated in various common tasks. A digitized biometric characteristic can be acquired rapidly, transmitted and stored in one or more databases, and then compared against information in various other one or more databases.
Independent of the biometric methodology used, the identification verification process initially requires a record of a person's unique characteristic is captured and stored in a database. When identification verification is required, a new record is captured and compared with the previous record in the database.
A biometric system can be either an “identification” system (e.g., to determine a person's identity) or a “verification” system (e.g., to verify a person's identity). The verification process requires capturing of raw biometric by a sensing device. This raw biometric is subsequently processed to extract the distinguishing biometric information, for example a fingerprint, from the raw biometric sample (i.e., image), and to convert it into a processed biometric identifier record. The record may typically be referred to as “biometric sample” or biometric “template.” This is typically an encrypted mathematical representation of the original information or a representation of a subset of the characteristics after application of selective criteria. The biometric template may then be registered in a suitable storage medium for future use in making a comparison during an authentication request. For commercial applications, the original biometric information cannot be reconstructed from the stored/registered biometric template.
The biometric information preferably should satisfy a number of characteristics: 1) all individuals (with possibly limited exemptions) can present it; 2) the biometric information should be stable, and thus should not change with time and physiological condition; 3) it should be readily measurable, meaning acquisition of the information should be fast and straightforward; 4) the information should be distinctive or unique to each individual; 5) the information should be transformable, meaning that it should be capable of being reduced to a file that cannot be used for reconstruction of the original information; 6) the information should be digitally comparable to information from others; and 7) the information should be reliable, as well as difficult to imitate by an unauthorized individual and tamper resistant. Various other characteristics are also desirable for any system/method that hopes to obtain acceptance by the general public. Such characteristics/traits may extend to the satisfaction of privacy laws and generally accepted ethical codes and present day ethical norms.
The processing of the information of the recorded raw biometric trait to obtain the biometric template can be limited by the quality of the raw information obtained. For example, the fingerprint pattern (ridges and bifurcations of the finger) can be recorded using light, heat-emission or pressure analysis sensors. Common problems such as contamination, weathering and misuse of the sensor can modify locally the raw information, which will likely affect, at least somewhat, the quality of the identification process. When the biometric template is compared to the stored biometric templates, a matching numeric score is generated to confirm or deny the identity of the user. The threshold numeric score can be selected based on the desired level of accuracy for the system, as measured by the False Acceptance Rate and False Rejection Rate. It is apparent that one would want to minimize false rates. However, if the quality of the recorded raw biometric trait is not sufficient, the generated score will be lower which may lead to false readings.
It should be apparent that the accuracy of a biometric system is directly related to the instrumentation and method used to acquire the raw biometric trait. In addition, each characteristic trait used for identification can provide a varying degree of accuracy in conjunction with the possible method used for recording the raw biometric trait. To improve the overall decision accuracy, more than one biometric trait can be recorded and used for identification. Such systems are typically referred to as “multimodal biometric systems.” An additional benefit of using multimodal systems is that such systems have an inherent resistance to being fooled by fraudulent data sources, such as imitation fingers, to obtain unauthorized access. There have been a number of disclosures of such systems. One specific example of an existing multimodal system incorporates the simultaneous utilization of a fingerprint and a finger-vein and/or palm-vein pattern. It is the understanding of the co-inventors of the present disclosure that all fingerprint, finger-vein and palm-vein identification system disclosed up to the present time require complete or partial contact of the finger or palm with the sensor of the biometric system. The need to have contact with the system presents, among other practical issues, potential health concerns (such as unintended or intended origination of infection) as well as contamination of the sensor as discussed previously. It would be clearly highly preferred by both users and system operators if the biometric identification process could be performed by non-contact means. The innovations of the present disclosure are focused around meeting this challenge with new systems and methods that do not require physical contact of a body part of an individual with the sensor element of a biometric system and also provide higher accuracy and resistance to spoofing.